1. Field Of The Invention
This inventioon relates to rimfire firearms and more particularly to a rimfire firearm receiver with a bolt action having a flexible feeding ramp in the receiver, a non-rotating cartridge extractor-guide, and an axially aligned firing pin carrier assembly having an off center firing pin.
2. Brief Description Of The Prior Art
Firearm bolt actions are known in the prior art and typically comprise a receiver defining an elongated chamber and a bolt slidably received within the chamber. The bolt has one or more lugs radially extending therefrom adjacent one end which slidably engage one or more elongated locking lug grooves formed in the receiver. This allows the bolt to slide with respect to the receiver between an open position, wherein a cartridge may be inserted into the receiver, and a closed position wherein the bolt forces the cartridge into a firing chamber. In order to lock the bolt in the closed position, the receiver also has an annular locking lug recess extending around the periphery of the elongated chamber to accommodate the locking lug when the bolt is in the closed position. This allows the bolt to be rotated through a given angle to move the locking lug out of alignment with the locking lug groove in the receiver.
The locking lugs for locking the bolt in the firing position are customarily made integral with the bolt handle and secured at the rear portion of the bolt. The bolt handle locking lug assembly mounted on the bolt is then oriented in a plane substantially perpendicular to the axis of the bolt and receiver. In locking the bolt relative to the receiver the bolt slides longitudinally so that the locking surfaces on the bolt and receiver are generally in the same plane at which time the bolt is rotated to bring the locking surfaces into engagement. Clearances must be provided to permit the sliding and rotational movement of the bolt with respect to the receiver. The inherent design and manufacturing clearances and tolerances and the extended distance between the front end and rear locking lug assembly of the bolt produce accuracy destroying vibrations when the cartridge is fired.
Due to the relatively low velocity of rimfire cartridges, the vibrations associated with the firing sequence limits the accuracy of the firearm by causing movement of the firearm while the bullet is still moving out of the barrel. Additionally, due to the cartridge being ignited by a blow to the rim the firing pin, its main spring and sear are arranged substantially off the longitudinal center line of the receiver thus adding to the vibration problem by allowing the firing mechanisms total energy to be applied off center to the longitudinal center line of the receiver and barrel.
It is also known in prior art rimfire firearms to provide fixed feeding or loading ramps or guides integral with the receiver and cooperating with the rear of the barrel to insure positive feeding of the cartridge into the chamber. The feeding ramp is generally a fixed assembly mounted in the receiver and conforms to the bottom contour of the non-rotating bolt.
Poff U.S. Pat. No. 4,653,210 discloses a firearm bolt action and extractor.
Sullivan U.S. Pat. No. 3,027,672 discloses a firearm with an aluminum alloy receiver.
Nilsson U.S. Pat. No. 4,547,988 discloses a firearm system with a cylinder bolt mechanism.
Timari U.S. Pat. No. 4,454,672 discloses a lock mechanism for firearm bolt action.
Chambers U.S. Pat. No. 2,139,648 discloses a firearm bolt action and locking mechanism.
Zedrosser U.S. Pat. No. 4,555,860 discloses a rifle breech assembly and shell extractor.
Waters U.S. Pat. No. 4,272,902 discloses a rifle bolt assembly and shell extractor.
Mondragon U.S. Pat. No. 557,079 discloses a breech loading bolt gun.
Stamm U.S. Pat. No. 1,124,071 discloses a straight pull lock for military rifles.
Payne U.S. Pat. No. 1,352,412 discloses a rimfire rifle With shell extractor.
Ahern U.S. Pat. No. 4,555,860 discloses a swing bolt action rifle.
Johnson U.S. Pat. No. 2,409,569 discloses an automatic rifle with reciprocating breech block.
Taylor U.S. Pat. No. 2,717,535 discloses a bolt action rifle and breech assembly.
Dixon U.S. Pat. No. 2,811,902 discloses a bolt action rifle and breech assembly.
Reed U.S. Pat. No. 2,941,449 discloses a decelerating device for a bolt action rifle.
Gitchell U.S. Pat. No. 3,253,362 discloses a bolt action rifle and breech assembly.
Clark U.S. Pat. No. 3,848,351 discloses a bolt action rifle and extractor assembly.
Lehner Austrian patent No. 759051/393 discloses a bolt action rifle and extractor assembly.
The present invention is distinguished over the prior art in general, and these patents in particular by a receiver assembly for a firearm which slidably and rotatably carries a bolt having a non-rotating cartridge extractor-guide at the forward end that allows the bolt to rotate relative thereto and the bolt head has locking lugs which engage a locking surface in the forward or barrel end of the receiver when the bolt is in the firing position. A flexible feeding ramp in the firing chamber surrounds the extractor and serves as a cartridge guide and pre-loads the bolt axially in the firing position. A firing pin carrier assembly provides axial center line absorption of the firing mechanism forces while providing an off center firing pin tip required for rimfire ammunition. During the initial firing sequence the feeding ramp absorbs vibrations caused by the moving components of the firing mechanisms and the impact of the firing pin and the subsequent shock of ignition, and bullet movement. During the latter stages of the firing sequence the firing pin carrier assembly absorbs the shock of the firing pin cocking rod and sear assemblies thus reducing after shock vibration and contributing to firearm accuracy.